Seed yield is a very complex trait and can be further dissected into several component traits, which are controlled by many interacting factors and pathways. Genes contributing to a complex crop trait such as yield can be numerous, making it extremely difficult to find genes that could be used to enhance yield through low throughput transgene discovery and validation process.
Additionally, grain yield in Zea mays is dependent upon the number of ovaries which are initiated, are fertilized and develop to maturity. Reduced grain production may result from, inter alia, a decrease in the number of kernel initials, restricted or untimely silk exsertion and/or kernel abortion during grain development. Maize silks comprise the stigmatic tissues of the flower, intercepting air-borne pollen and supporting pollen tube growth to result in fertilization. Importantly, the process of fertilization determines kernel number and thus sets an irreversible upper limit on grain yield.
One of the important keys to successful high throughput (HTP) evaluation of yield enhancing genes is the ability to eliminate genes that do not positively affect yield. However, measuring yield has been proven difficult because of the huge variation in yield associated with pollination and magnified plant to plant variation in greenhouse studies. This invention describes a new approach that is able to circumvent these problems and that makes the HTP evaluation of yield enhancing genes feasible.